The driver doesn't need the bytesused argument.

For decoders, the plane bytesused is known and therefore,
buf_prepare is used to set it. For encoders, it's
handled by the codec_ops.done hook.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>